I have to agree with Sean Carroll’s assessment of Sam Harris’ recent TED talk (Sam was apparently no amused):

Simply put, a moral system is a strategy, and while some strategies may work better than others, they tend to be context dependent. The efficacy of any moral edict is contingent on the strategic landscape in which it functions. This basic fact of moral systems makes me incredibly skeptical of attempts to derive a universal moral system that is optimum for all times, all geographies, and all cultural histories.